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freebsd-skq/sys/vm/swap_pager.h

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/* -> /*- for license, minor formatting changes
2005-01-07 02:29:27 +00:00
/*-
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* Copyright (c) 1990 University of Utah.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
* from: @(#)swap_pager.h 7.1 (Berkeley) 12/5/90
$Id$ -> $FreeBSD$
1999-08-28 01:08:13 +00:00
* $FreeBSD$
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
Use correct _VM_SWAP_PAGER_H_ to check for multiple inclusion.
2003-01-03 14:22:52 +00:00
#ifndef _VM_SWAP_PAGER_H_
#define _VM_SWAP_PAGER_H_ 1
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
- Move 'struct swdevt' back into swap_pager.h and expose it to userland. - Restore support for fetching swap information from crash dumps via kvm_get_swapinfo(3) to fix pstat -T/-s on crash dumps. Reviewed by: arch@, phk MFC after: 1 week
2007-02-07 17:43:11 +00:00
typedef int32_t swblk_t; /*
* swap offset. This is the type used to
* address the "virtual swap device" and
* therefore the maximum swap space is
* 2^32 pages.
*/
struct buf;
struct swdevt;
typedef void sw_strategy_t(struct buf *, struct swdevt *);
typedef void sw_close_t(struct thread *, struct swdevt *);
/*
* Swap device table
*/
struct swdevt {
int sw_flags;
int sw_nblks;
int sw_used;
dev_t sw_dev;
struct vnode *sw_vp;
void *sw_id;
swblk_t sw_first;
swblk_t sw_end;
struct blist *sw_blist;
TAILQ_ENTRY(swdevt) sw_list;
sw_strategy_t *sw_strategy;
sw_close_t *sw_close;
};
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
#define SW_UNMAPPED 0x01
- Move 'struct swdevt' back into swap_pager.h and expose it to userland. - Restore support for fetching swap information from crash dumps via kvm_get_swapinfo(3) to fix pstat -T/-s on crash dumps. Reviewed by: arch@, phk MFC after: 1 week
2007-02-07 17:43:11 +00:00
#define SW_CLOSING 0x04
Make struct swblock kernel only, to make vm/swap_pager.h userland includable. Move struct swdevt from sys/conf.h to the more appropriate vm/swap_pager.h. Adjust #include use in libkvm and pstat(8) to match.
2003-01-03 16:23:12 +00:00
#ifdef _KERNEL
Fix argument passing to the "freeer" routine. Added some prototypes. (bde) Moved extern declaration of swap_pager_full into swap_pager.h and out of the various files that reference it. (davidg) Submitted by: bde & davidg
1995-10-07 19:02:56 +00:00
extern int swap_pager_full;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
extern int swap_pager_avail;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
struct xswdev;
int swap_dev_info(int name, struct xswdev *xs, char *devname, size_t len);
Remove __P.
2002-03-19 22:20:14 +00:00
void swap_pager_copy(vm_object_t, vm_object_t, vm_pindex_t, int);
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
vm_pindex_t swap_pager_find_least(vm_object_t object, vm_pindex_t pindex);
Remove __P.
2002-03-19 22:20:14 +00:00
void swap_pager_freespace(vm_object_t, vm_pindex_t, vm_size_t);
void swap_pager_swap_init(void);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
int swap_pager_isswapped(vm_object_t, struct swdevt *);
Remove __P.
2002-03-19 22:20:14 +00:00
int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_size_t);
Add a new function swap_pager_status() which reports the total size of the paging space and how much of it is in use (in pages). Use this interface from the Linuxolator instead of groping around in the internals of the swap_pager.
2003-07-18 10:26:09 +00:00
void swap_pager_status(int *total, int *used);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
void swapoff_all(void);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
- Remove a number of extra newlines that do not belong here according to style(9) - Minor space adjustment in cases where we have "( ", " )", if(), return(), while(), for(), etc. - Add /* SYMBOL */ after a few #endifs. Reviewed by: alc
2002-03-10 21:52:48 +00:00
#endif /* _KERNEL */
Use correct _VM_SWAP_PAGER_H_ to check for multiple inclusion.
2003-01-03 14:22:52 +00:00
#endif /* _VM_SWAP_PAGER_H_ */
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